Device and Method for Multi-Sim Wireless Communication

1. A user equipment (UE), comprising: a subscriber identity module (SIM) configured to perform communication with a serving cell of a network in a radio resource control (RRC) idle mode; and a processor configured to: trigger measurement of a neighbor cell signal based on a neighbor cell measurement rule that considers a measurement value of a serving cell signal and a number of cell reselection ping-pongs involving the UE that occurred between the serving cell and the neighbor cell in the RRC idle mode; determine a threshold value according to the number of cell reselection ping-pongs between the serving cell and the neighbor cell involving the UE, and a weight value for the number of cell reselection ping-pongs, wherein the measurement of the neighbor cell signal is triggered when the measurement value is less than or equal to the threshold value; and reselect the neighbor cell based on at least one cell reselection criterion considering the measurement value and the number of cell reselection ping-pongs.

2. The UE of claim 1, wherein the measurement value is a first measurement value, and the processor is further configured to: measure the neighbor cell signal; and obtain a second measurement value for the neighbor cell signal.

3. The UE of claim 2, wherein the serving cell signal is a reference signal of the serving cell, the neighbor cell signal is a reference signal of the neighbor cell, the first measurement value comprises a measurement value of reference signal received power (RSRP) or reference signal received quality (RSRQ) of the reference signal of the serving cell, and the second measurement value comprises a measurement value of RSRP or RSRQ of the reference signal of the neighbor cell.

4. The operating method of claim 3, wherein the at least one cell reselection criterion is determined according to radio access technology (RAT) types and frequency characteristics of the serving cell and the neighbor cell.

5. The UE of claim 1, wherein the neighbor cell is a first neighbor cell, and an interim number of cell reselection ping-pongs is initialized to 0 when the number of cell reselection ping-pongs equals or exceeds 1 and the UE reselects a second neighbor cell.

6. The UE of claim 1, wherein the communication with the serving cell of the network corresponds to 4th-Generation (4G) Long Term Evolution (LTE) network communication or 5th-Generation (5G) New Radio (NR) network communication.

7. An operating method of a user equipment (UE), comprising: performing communication associated with a subscriber identity module (SIM) of the UE with a serving cell of a network in a radio resource control (RRC) idle mode; triggering measurement of a neighbor cell signal based on a neighbor cell measurement rule that considers a measurement value of a serving cell signal and a number of cell reselection ping- pongs involving the UE that occurred between the serving cell and the neighbor cell; reselecting the neighbor cell based on at least one cell reselection criterion considering the measurement value and the number of cell reselection ping-pongs; and triggering measurement of the neighbor cell signal when the measurement value is less than or equal to a threshold value, wherein the threshold value is determined according to the number of cell reselection ping-pongs between the serving cell and the neighbor cell involving the UE, and a weight value for the number of cell reselection ping-pongs.

8. The operating method of claim 7, wherein the threshold value is inversely proportional to each of the number of cell reselection ping-pongs and the weight value.

9. The operating method of claim 8, wherein the threshold value is proportional to a number of times that the measurement of the neighbor cell signal is repeated.

10. An operating method of a user equipment (UE), comprising: performing communication associated with a subscriber identity module (SIM) of the UE with a serving cell of a network in a radio resource control (RRC) idle mode; triggering measurement of a neighbor cell signal based on a neighbor cell measurement rule that considers a measurement value of a serving cell signal and a number of cell reselection ping- pongs involving the UE that occurred between the serving cell and the neighbor cell in the RRC idle mode; and reselecting the neighbor cell based on a plurality of cell reselection criteria considering the measurement value and the number of cell reselection ping-pongs, wherein the plurality of cell reselection criteria are classified according to a frequency type between the serving cell and the neighbor cell, and the frequency type is classified into (i) an inter-frequency type or an inter system-frequency type; and (ii) an intra-frequency type.

11. The operating method of claim 10, further comprising: receiving information about a frequency priority of the neighbor cell from the network; and determining whether the frequency priority of the neighbor cell is lower than a frequency priority of the serving cell when the frequency type is the inter-frequency type or the inter system- frequency type.

12. The operating method of claim 11, wherein the plurality of cell reselection criteria comprise a first cell reselection criterion, and the measurement value is a first measurement value, and the operating method further comprises obtaining a second measurement value for the neighbor cell signal, and reselecting the neighbor cell based on the first cell reselection criterion when the frequency priority of the neighbor cell is determined to be lower than the frequency priority of the serving cell, wherein the first cell reselection criterion is a criterion of the first measurement value being less than a second threshold value and the second measurement value being greater than a third threshold value.

13. The operating method of claim 11, wherein the plurality of cell reselection criteria comprise a second cell reselection criterion, and the operating method further comprises reselecting the neighbor cell based on the second cell reselection criterion when the frequency priority of the neighbor cell is determined to be the same as or higher than the frequency priority of the serving cell.

14. The operating method of claim 13, wherein the second cell reselection criterion is determined according to the number of cell reselection ping-pongs between the serving cell and the neighbor cell and a weight value for the number of cell reselection ping- pongs, and the number of cell reselection ping-pongs and the weight value are proportional to a number of times that the measurement of the neighbor cell is repeated.